DSpace@MIT: Acoustic function of sound hole design in musical instruments Acoustic function of sound hole design in musical instruments Research and Teaching Output of the MIT Community → View Item JavaScript is disabled for your browser. Some features of this site may not work without it. Acoustic function of sound hole design in musical instruments Other Contributors: Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Advisor: Nicholas C. Makris. Department: Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Publisher: Massachusetts Institute of Technology Date Issued: 2010 Abstract: Sound-hole, an essential component of stringed musical instruments, enhances the sound radiation in the lower octave by introducing a natural vibration mode called air resonance. Many musical instruments, including those from the violin, lute and oud families have evolved complex sound-hole geometries through centuries of trail and error. However, due to the inability of current theories to analyze complex sound-holes, the design knowledge in such sound-holes accumulated by time is still uncovered.

Here we present the potential physical principles behind the historical development of complex sound-holes such as rosettes in lute, f-hole in violin and multiple sound-holes in oud families based on a newly developed unified approach to analyze general sound-holes. We showed that the majority of the air flow passes through the near-the-edge area of the opening, which has potentially led to the emergence of rosettes in lute family. Consequently, we showed that the variation in resonance frequency and bandwidth of different traditional rosettes with fixed outer diameter is less than a semitone, while the methods based on the total void area predicts variations of many semitones. Investigating the evolution of sound-holes in violin family from circular geometry in at least 10th century to the present-day f-hole geometry, we found that the evolution is consistent with a drive toward decreasing the void area and increasing the resonance bandwidth for a fixed resonance frequency. We anticipate this approach to be a starting point in discovering the concepts behind the geometrical design of the existing sound-hole geometries, and helping the musicians, instrument makers and scientists utilize this knowledge to design consistently better instruments. Description: Thesis (S.M.)--Massachusetts Institute of Technology, Dept.

of Mechanical Engineering, 2010.; Cataloged from PDF version of thesis.; Includes bibliographical references (p. 69-70). 11d: Stringed Instruments | SOUND Skip to content 11d: Stringed Instruments There are probably an infinite number of ways to connect a string to a resonating body to form a musical instrument and any number of body shapes. Here is Wikipedia’s list of stringed instruments with links to information about each one. There are also several variations in how the string is excited and how the string vibration is coupled to the body of the instrument. It is also possible to turn the vibrations into an electronic signal for amplification, as we will see later. Stringed instruments have strings with string harmonic resonances connected to a surface which has additional overtones, some of which are not harmonic. Most stringed instruments also have a hollow body with an opening (called the f hole or sound hole in a violin and some guitars) so there are air resonances associated with the body cavity; the Helmholtz resonances we saw in Chapter 4 and mentioned above. The shape of the hole developed over timemby trial and error to provide the most sound as explained in this article .

It is this combination of string, surface and Helmholtz resonances that make each type of instrument, and in fact each instrument unique. A primary difference between expensive violins such as a Stradivarius build in the late 1600s, early 1700s (worth millions of dollars) and a cheaply made modern violin is that the resonance frequencies of the Stradivarius are more distinct, have a larger amplitude and are closer to the frequencies of the notes played by the string. These resonances make it easier to reach a given note and the note being played sounds louder. (It should be noted, however, that blind listening tests can rarely distinguish between a Stradivarius and a well-made modern instrument selling for tens of thousands of dollars.) For most stringed instruments the bridge transmits vibrations from the string to the body of the instrument (electrical pickups will be discussed later). Many guitar and violin bridges are carved with interesting shapes. This makes them more flexible so that they are closer to the resonance frequencies of the string and body. This also means, however, that they can act as filters since they do not transmit some frequencies as easily.

Some bridges are slightly rounded so that the length of the string changes slightly as the string vibrates. This will also affect the frequencies emitted by the instrument. In the picture on the left below the bridge of a double bass is the light colored piece. On the right is the bridge of a modern guitar. One problem that occurs for some stringed instruments, particularly the cello, is an unwanted resonance of the bridge, string, and body called a wolf tone. The result is an unpleasant, wavering note. For certain notes, energy from the string causes a resonance in the bridge and body that feeds back into the string, making the string hard to control. Beginning performers often have more trouble controlling these unwanted resonances than experienced musicians. Various design changes have been tried to avoid this problem but it is very difficult to construct an instrument with resonances only where desired and no others. When the string vibrations are up and down relative to the bridge, energy is transmitted to the body more efficiently so the sound dies away more quickly. If the string is plucked in a direction parallel to the body the sound is softer but lasts longer because the bridge is less efficient in transmitting the vibrations.

The schematic below shows the effect of the direction in which the string is plucked or bowed (blue arrows) relative to the body surface of the instrument. The top surface of most stringed instruments is smooth and flat but guitars, violins and other instruments have reinforcing bars on the inside that strengthen the top and carry vibrations from the bridge area to the rest of the surface. For guitars this is called guitar bracing, for violins the reinforcing bars are called bass bars. Instrument makers generally try to construct these so that they do not cause unwanted resonances while reinforcing desired frequencies in the instrument but this is largely a trial and error process. The knowledge gained from this process has been handed down over many generations and there are at least half a dozen major bracing stiles for guitars with many small variations of these. The following picture shows the bracing inside a guitar. Many hollow bodied stringed instruments also have a sound post. This is a small dowel inside the instrument wedged between the top to the bottom surfaces. The purpose is to conduct vibrations from the top surface to the bottom. Placement and size of the sound post is also determined largely by trial and error. Both sound bars and sound posts affect the resonance frequencies and overall sound of the instrument.

Placing the sound post closer to the neck of a violin makes the tones louder; moving it further from the neck changes the tonal quality to be more rich by transmitting more overtone frequencies from the top to the bottom of the instrument. The sound post transmits lower frequencies more effectively with the result that high frequencies are emitted mostly by the top of a guitar or violin but low frequencies are emitted from both sides. In the schematic below the cross section of a violin is shown. The bass bar runs the length of the violin and the sound post connects the top to the bottom surface. Notice that bass bar and sound post are positioned so that as the bridge rocks back and forth due to vibration of the strings the bridge will transmit energy to both the bass bar and the sound post. The asymmetric location of the sound post also means the top surface is more likely to vibrate with the left side out of phase with the right side (left side going up at the same time the right side is going down). This affects the Helmholtz resonances of the cavity inside. The Helmholtz resonances affect the volume of certain frequencies being produced.

If the air is coming out of the f hole due to a Helmholtz resonance at the same time the instrument body top is vibrating downward (the two motions are 180 degrees out of phase), the exiting air will end up at a higher pressure and thus a higher volume. This effect is stronger for lower frequencies because the Helmholtz resonances tend to be lower frequency, around 270 Hz for a violin. Another factor that affects the sound of a string instrument is the material of which it is constructed and the finish. More expensive guitars and violins are made from wood that is picked to be very dense and have very uniform and fine grain. The more uniform the wood grain the less likely there will be an unwanted resonance. It has been claimed that the famous Stradivarius violins have a special sound in part because the wood was treated with special chemicals. The process of how they were made was a secret that was lost hundreds of years ago and has not been replicated. Strictly speaking keyboard instruments such as the piano, harpsichord and clavichord are classified as percussion instruments because there is a mechanism that strikes or plucks the string.

In the clavichord, developed in the 15th century, a small metal piece called the tangent hits the string (sometimes two strings) when a lever is pressed by the performer. The harpsichord was developed in about a century later and uses a quill (originally from the feather of a bird) called the plectrum to pluck one or two strings when the key is pressed. A spring mechanism moves the plectrum out of the way while the mechanism returns to its starting point (see Wikipedia for details). The piano was developed in the early 1700s. This instrument overcame several limitations of the earlier harpsichords and clavichords. Because it was significantly louder it was originally called the ‘piano forte’ (forte is Latin for loud). Below is a very simplified diagram of the mechanism of the strike action of the piano (more details can be found on Wikipedia). When the key is pressed a series of levers acts to throw the hammer upward so that it hits the string. The back check keeps the hammer from bouncing back and striking the string twice. As long as the key is held down another set of levers keeps the damper off the string.

The clavichord, harpsichord and piano sound different in large part because the strings are set into vibration by different mechanisms. As we saw above, the initial shape of the string when it is plucked or struck determines which harmonics are more present. For the piano the harmonic that has an anti-node where the hammer strikes is dampened out because the hammer contact prevents the string from vibrating at that location, forming a temporary node. The piano also has a number of other innovations that give it a distinct sound. The mechanism of the piano allows the hammer to strike the strings at a different angle depending on how hard the key is pushed. The surface of the hammer is made of felt and different regions have slightly different stiffness’s of felt. So pushing a key harder not only causes the hammer to strike harder, it also causes a stiffer part of the hammer to strike the string, giving a louder sound and activating other harmonics. Pianos also have three strings for every note the piano plays. Normally all three strings are struck by the hammer but when the left foot petal is held down the hammer shifts so that only two strings are struck. In this case the third is activated by vibrations traveling from the other two through the frame that holds the strings.

Since the strings can vibrate in different directions at the same time, transmitting energy at different rates and to different resonances in the piano body, the sound of a piano is much richer than instruments that sound only one string at a time. In the first picture below the strings are all moving up at the same time. In the second picture the third string is moving down while the other two are moving upwards. In the third picture the third string is moving in a direction perpendicular to the motion of the other two strings. Obviously there can be other combination of vibrations. The piano also plays a larger range of notes than the harpsichord or clavichord. To archive the high notes the tension must be very high in the strings, as much as 1000 N for some strings. To withstand these forces the strings in a piano are attached to a cast iron frame. For strings under this much tension even slight displacements from equilibrium (when the hammer strikes the string) cause a significant change in the tension. This means that striking the note harder changes the pitch slightly because the string is stretched more. The effect is greater on higher harmonics because a higher harmonic has more bends along the length of the string, increasing the tension even more.

The result is that the overtones are no longer exactly harmonic. A second problem for a stringed instrument that plays very low notes is that for a given string density and tension, the strings have to be unreasonably long to play the lowest notes. In order to shorten the length of string needed for low notes the strings are made more dense by wrapping them either once or twice. Even with these adjustments a grand piano is quite large. Upright pianos put the strings into layers so that more strings can be packed into a smaller space. The wires shown below are double wrapped piano wires. As with all stringed instruments the body of the piano acts as a resonator to amplify the sound of the vibrating strings (of course, at the cost of having the string vibrate for less time so that conservation of energy is obeyed). Pianos have a soundboard attached to the frame that holds the strings. Much like guitar bracing, the soundboard also has bracing that helps transmit the sound through the entire surface. The top of the piano serves two purposes. One is to reflect sound from the soundboard out towards the audience. The piano top also has resonant modes, just like those of a guitar or violin body that affect the frequencies being transmitted.

Other Resources: Guitar holes vs. violin holes - Everything2.com Guitar holes vs. violin holes by Halcyon&on Sat Jul 08 2000 at 2:40:51 Why the sound holes on violins and arch-top guitars are "f" shaped, and the sound holes on flat-top guitars are round. The main considerations when looking at the sound-holes in guitars and violins are their shape, size and position. Guitars with round sound-holes are different instruments from those with "f"-shaped sound-holes. The fundamental problem with guitars is that the stresses of the strings distort the instrument by both bending and twisting it. Flat-topped guitars--typically Spanish (or classical), flamenco and folk guitars --have round sound-holes. They are lightly built and usually have gut or nylon strings. Distortion of the body is prevented by bracing structures around the inside of the soundhole. In these guitars, a round sound-hole offers the best structural solution while giving the best projection and volume. guitars Most flat-topped guitars are based on the designs of Antonio de Torres Jurado , a famous 19th-century guitar maker.

However, there is an alternative to this type of guitar. The Ovation guitar has 11 small holes at each side near the neck rather than one central round sound-hole. These holes eliminate feedback if the guitar has an acoustic microphone. The arch-top guitars with "f" holes use metal strings, are of heavier build, and do not have the tonal qualities or projection of flat-top guitars. This is because in the past, these guitars were mainly rhythm instruments that were thumped rather than played. The "f"-shaped sound-holes allow a solid strut to extend the length of the guitar body, giving it the necessary strength. However, this changed when electric guitars took over from standard acoustic ones. Electric guitars have electronic sound pickups instead of sound-holes. The body of an electric guitar must be rigid, because vibration will distort the sound. When a guitar is played electrically sound-holes serve no useful purpose. Some players, typically jazz musicians, prefer the semi-acoustic guitar, which has both pickups and "f" holes. These can be practised on acoustically yet performances can be amplified electronically. These guitars obviously still require the sound-hole. However, the overall trend is towards solid guitars which have no holes.

violins Violins do not have the option of a round sound-hole, as the pressure the musician places on the bridge while holding the instrument would be likely to distort the body if it had a central hole. The violin also requires internal bracing that is better offered by the "f"-hole design. Some string instruments like the banjo have the sound-hole at the back. The one-string fiddle has no body, but uses a horn and diaphragm . As for the appearance of the "f"-shaped design, this is probably related to the musical character for fortissimo , rather than any acoustic benefit. Source: The NewScientist - LastWord Power efficiency in the violin | MIT News Power efficiency in the violin New study identifies key design features that boost violins’ acoustic power. Jennifer Chu | MIT News Office February 10, 2015 Media can only be downloaded from the desktop version of this website.

Share Leave a comment Some of the most prized violins in the world were crafted in the Italian workshops of Amati, Stradivari, and Guarneri — master violinmaking families from the 17th and 18th centuries who produced increasingly powerful instruments in the renaissance and baroque musical eras. These violins, worth millions of dollars today, represent the Cremonese period — what is now considered the golden age of violinmaking. Now acousticians and fluid dynamicists at MIT, along with violinmakers at the North Bennet Street School in Boston, have analyzed measurements from hundreds of Cremonese-era violins, identifying key design features that contribute to these particular violins’ acoustic power, or fullness of sound. The team acquired technical drawings of Cremonese-era violins from museums, collector databases, and books, as well as X-ray and CAT scans of the instruments. They compared the dimensions of various features from one instrument to another, as well as measurements of acoustic resonances across instruments.

The researchers found that a key feature affecting a violin’s sound is the shape and length of its “f-holes,” the f-shaped openings through which air escapes: The more elongated these are, the more sound a violin can produce. What’s more, an elongated sound hole takes up little space on the violin, while still producing a full sound — a design that the researchers found to be more power-efficient than the rounder sound holes of the violin’s ancestors, such as medieval fiddles, lyres, and rebecs. The thickness of a violin’s back plate also contributes to its acoustic power. Violins carved from wood are relatively elastic: As the instrument produces sound, the violin’s body may respond to the air vibrations, contracting and expanding minutely. A thicker back plate, they found, would boost a violin’s sound. The researchers found that as violins were crafted first by Amati, then Stradivari, and finally Guarneri, they slowly evolved to more elongated f-holes and thicker back plates. But were the design changes intentional?

To answer this question, the researchers worked the measurements from hundreds of Cremonese-era violins into an evolutionary model, and found that any change in design could reasonably be explained by natural mutation — or, in this case, craftsmanship error. In other words, makers may have crafted violins with longer sound holes and thicker back plates not by design, but by accident. “We found that if you try to replicate a sound hole exactly from the last one you made, you’ll always have a little error,” says Nicholas Makris, a professor of mechanical and ocean engineering at MIT. “You’re cutting with a knife into thin wood and you can’t get it perfectly, and the error we report is about 2 percent … always within what would have happened if it was an evolutionary change, accidentally from random fluctuations.” Makris stresses that while each violinmaker inarguably possessed a good ear — in order to recognize and replicate the violins that sounded best — whether they recognized the particular design elements that contribute to a more powerful sound is still up for debate. “People had to be listening, and had to be picking things that were more efficient, and were making good selection of what instrument to replicate,” Makris says.

“Whether they understood, ‘Oh, we need to make [the sound hole] more slender,’ we can’t say. But they definitely knew what was a better instrument to replicate.” Makris and his colleagues from MIT and the North Bennett Street School publish their results this week in the Proceedings of the Royal Society: A. There’s power in shape Makris didn’t originally set out to study violin acoustics: His work is primarily in ocean exploration with acoustics, developing and applying technology to sense marine life and ocean phenomenon over large areas. But about a decade ago, he took up a new hobby, playing the lute. “I’m an acoustics expert, but promised myself I wouldn’t think about the acoustics of the instrument, I’m just going to play the thing,” Makris remembers. That thinking didn’t last long, as Makris started talking with lutemakers and players in an effort to better understand the instrument — which was once Europe’s most popular, but became effectively extinct for centuries before its recent re-emergence.

The lute is much quieter than the violin: In addition to other design differences, its sound holes are circular rather than f-shaped, with elaborate interior carvings known as rosettes, inherited from the lute’s Middle Eastern ancestor, the oud. Several years ago, a noted lute player approached Makris with an intriguing quandary: Do the carvings within a lute’s sound hole make a difference to the overall sound produced? Makris realized that the relevant frequencies of sound were in the range where airflow through the sound hole behaves nearly as an incompressible fluid, and enlisted the help of Yuming Liu, a principal research scientist in MIT’s Department of Mechanical Engineering. The team modeled the airflow through a simple round hole, as well as a more elaborately patterned hole of the same diameter, and found that in both cases, the air flowed fastest at the hole’s periphery; its interior, whether open or partially filled, did not significantly affect the airflow.

Answering the musician’s simple question turned into a seven-year project in which the team examined the acoustic dynamics of stringed instruments through time, from the oud, lute, and medieval fiddles to the guitar and ultimately the violin — a period spanning from the 10th century to the 18th century. Analysis of the violin came at the urging of team member Roman Barnas, director of violinmaking and repair at the North Bennet Street School, an expert on the construction of early instruments. Throughout the 800-year period the researchers examined, they noted an evolution in sound-hole shape — from a simple round hole to a semicircle, which eventually morphed into a c-shape that grew more elongated, ultimately assuming the f-shape of the violin. The perimeter of these shapes steadily grew, while the area of the interior void gradually decreased. As with the evolution in length of the violin’s f-hole during the Cremonese period, Makris’ team found that the overall shape of the violin’s ancestors slowly evolved to be more powerful and more acoustically efficient — though not necessarily by design. “We think these changes are still within the possibility of natural mutation,” Makris says.

“All of these subtle parameters of shape, we’ve modeled, and are able to make very good predictions on what the effects will be on frequency and power.” Makris says the group’s results may be useful for master violinmakers looking to design more powerful, fuller-sounding instruments — although he acknowledges that there’s more to producing a quality violin than adjusting a few parameters. “Mystery is good, and there’s magic in violinmaking,” Makris says. “Some makers, I don’t know how they do it — it’s an art form. They have their techniques and methods. But here, for us, it’s good to understand scientifically as much as you can.” This research was funded in part by the Office of Naval Research. Parts of the Violin and Their Function By Espie Estrella Updated March 22, 2016. In order to learn how to play the violin, you must first be well acquainted with the different parts of the violin and the specific functions of those parts. The parts of the violin are named just like a human body. It has a neck, belly (front of the violin), back and ribs (the sides of the violin).

The other parts of the violin are: Scroll - This is located at the top of the violin. It is a decorative part, mostly hand carved. Pegbox - This is where the pegs are inserted. The pegs are adjusted to tune the violin. Nut - Helps keep the distance of the strings and supports the strings so that it has a good height from the fingerboard. Strings - It has 4 strings that are tuned a fifth apart. Bridge - The position of the bridge is essential as it directly relates to the quality of sound produced by the violin. The bridge is held in place by the strings' tension. When the string vibrates, the bridge also vibrates. Fingerboard - It is a strip of wood on the neck of the violin where the strings are. When a violinist plays, he presses down the strings on the fingerboard, thus changing the pitch. continue reading below our video 10 Best Universities in the United States Sounding Post - Located under the bridge, it supports the pressure inside the violin. The bridge and sounding post are directly related, when the violin vibrates, the bridge, body and sounding post vibrates as well. F Holes - Is located in the middle of the violin.

It is called F Hole because it is shaped like an F in Italics. It allows sound to come out of the violin. Altering the F Hole, such as its length, can affect the sound of the violin. Tailpiece - Holds the strings so that it has a good distance from the bridge. Chin Rest - It helps the violinist hold the instrument in place. While playing, the violinist can use his chin to hold the violin, thus freeing up his hands. Here is an illustration of the parts of a violin from folkofthewood.com for further understanding. Violin-fiddling boffins learn that 'F-HOLES' are secret to Stradivarius' SUPERIOR sound • The Register Violin-fiddling boffins learn that 'F-HOLES' are secret to Stradivarius' SUPERIOR sound Acoustic dynamics of stringed instruments nailed 15 Feb 2015 at 12:30, John Leyden Scientists have identified the design features that boost the acoustic power of violins.

Italian workshops of master violin-making families (such as Stradivari) produced increasingly powerful instruments in the renaissance and baroque musical eras during the 17th and 18th centuries, the so-called Cremonese era. Advances in the manufacturing of violins happened mostly by accident rather than design, according to a new study by modern acousticians and fluid dynamicists at MIT. Boffins teamed up with violinmakers at the North Bennet Street School in Boston in the US to analyse measurements from hundreds of Cremonese-era violins, identifying key design features that contribute to these particular violins’ acoustic power, or fullness of sound. The team obtained technical drawings of Cremonese-era violins from museums, collector databases, and books, as well as X-ray and CAT scans of actual instruments. Dimensions of various features from one instrument to another, as well as measurements of acoustic resonances across instruments, were compared. The key to a Stradivarius violin’s sound turns out to revolve around its holes or more precisely “the shape and length of its ‘f-holes’, the f-shaped openings through which air escapes”, as a statement on the researchers work explains.

The more elongated these are, the more sound a violin can produce. What’s more, an elongated sound hole takes up little space on the violin, while still producing a full sound – a design that the researchers found to be more power-efficient than the rounder sound holes of the violin’s ancestors, such as medieval fiddles, lyres, and rebecs. The thickness of a violin’s back plate also contributes to its acoustic power. Violins carved from wood are relatively elastic: As the instrument produces sound, the violin’s body may respond to the air vibrations, contracting and expanding minutely. A thicker back plate, they found, would boost a violin’s sound. Violins slowly evolved to more elongated f-holes and thicker back plates because of these improved acoustic features. To find out if design changes were intentional the researchers fed the measurements from hundreds of Cremonese-era violins into an evolutionary model, finding that any change in design could reasonably be explained by natural mutation – or, in this case, craftsmanship error. Makers may have crafted violins with longer sound holes and thicker back plates not by design, but by accident, the researchers concluded.

“We found that if you try to replicate a sound hole exactly from the last one you made, you’ll always have a little error,” explained Nicholas Makris, a professor of mechanical and ocean engineering at MIT. “You’re cutting with a knife into thin wood and you can’t get it perfectly, and the error we report is about 2 per cent … always within what would have happened if it was an evolutionary change, accidentally from random fluctuations.” Although each violin maker inarguably possessed a good ear – in order to recognise and replicate the violins that sounded best – whether or not they recognised the particular design elements that contribute to a more powerful sound is still up for debate. In other words, the violinmakers knew what was a better instrument to replicate but they didn’t necessarily know that its slender holes were what made the sound it produced tonally pleasing. The scientists published their study, funded in part by the Office of Naval Research, in the Proceedings of the Royal Society. Makris got tuned into the field of research after taking up the lute. The lute, which effectively became extinct for centuries before its recent re-emergence, is much quieter than the violin.

Its sound holes are circular rather than f-shaped and featuring elaborate interior carvings known as rosettes. Answering a musician’s simple question about whether or not carvings within a lute’s sound hole make a difference to the overall sound produced morphed over time into a seven-year project examining the acoustic dynamics of stringed instruments through time. ® Sound hole | Define Sound hole at Dictionary.com sound hole noun 1. an opening in the soundboard of a musical stringed instrument, as a violin or lute, for increasing the soundboard's capacity for vibration. Origin of sound hole Examples from the Web for sound hole Expand Historical Examples Each country has its peculiar and native rendering of every sound hole that was first designed in Italy. Antonio Stradivari Horace William Petherick I don't say there's much in the hole; but it's a good, sound hole as far as it goes, and it can't have to go much further. Denis Dent Ernest W. Hornung British Dictionary definitions for sound hole Expand noun 1.

any of variously shaped apertures in the sounding board of certain stringed instruments, such as the `f' shaped holes of a violin Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 People invent new words all the time, but which ones actually make it? Word of the Day Illumin - The Violin: The Art Behind the Sound The Violin: The Art Behind the Sound By Farisha Salman The violin is regarded as one of the most important musical instruments in history, perhaps because of its fundamental role in an orchestra or the inspiration and emotion transferred to the listener upon hearing its powerfully romantic sound. While its construction concentrates on producing impeccable sound, had the violin not adhered to the laws of science, it would have been a failure as a musical instrument (Hughes).

Indeed, the violin is an amazing amalgam of science, mathematics, physics, and chemistry but it is strictly regulated by physical and acoustic laws. Nothing about the violin can be changed without seriously disturbing its equilibrium as an instrument of essential and precise assimilation. The History of the Violin The history of the violin can be traced back as far as the 9th century. Although violin-playing is best known in European countries, especially considering the origins of world famous violinists like Fritz Kreisler, Jascha Heifetz, and Niccolo Paganini, violins are believed to have originated in Asia [1]. The current form of the violin, however, evolved more than 500 years ago from several musical instruments. These precursors include rudimentary instruments called the Rebab, Rebec, and Ravanastron, played in Iran, Saudi Arabia, and India. The Rebec, a pear-shaped instrument, contributes some of its traits to the modern violin. Positioned at the neck and played with a bow like the violin, the Rebec has f-holes carved out from its body. In addition, like the violin, the strings of the Rebec are secured and tightened by pegs laterally inserted into a pegbox [2].

The Major Components of the Violin The violin is composed almost entirely of wood. It is shaped like a woman's body by design and has a bridge that is placed between the two f-holes (Fig. 1). Four strings, connected to a saddle, are positioned on the bridge, extended across the fingerboard, and tied into a pegbox at the opposite end. These strings can be metal, gut or a hybrid called synthetic core. Also, two f-holes are carved out from the body of the violin and at the end of the finger board, a scroll protrudes from the pegbox. Wikimedia Commons Figure 1: The parts of a violin is shaped like a woman's body and is usually made entirely of wood. The violin contains distinct components and understanding how each of these parts is connected to the violin as a whole is crucial. The major parts of the violin-- the body, bridge, strings and bow-- each contribute to the production of a violin's distinct sound. The Major Components of the Violin The Body There are four types of wood that generally make up the body: spruce, maple, ebony, and rosewood. The quality of wood used is important because flexible wood tends to shape well and projects the highest quality of sound.

A good wood will have been aged or air-dried in order to have the optimal moisture equilibrium with the environment. Wood lacking this quality will often be inflexible and crack during shaping, or worse, playing. The violin maker selects only the best trees by tapping the trunk with a hatchet to determine if that particular tree's wood will produce quality sound. Once the tree has been chopped down, it is stored in a ventilated place protected from seasonal change for as long as 20 years. In general, the wood chosen must be light in order to emit melodious sounds through decent resonant vibrations. In fact, heavier wood would actually thwart the energy essential to create quality sound. But at the same time, the wood must be strong enough to withstand the concentrated pressure exerted by its four strings on the bridge, which can be as high as 250 Newtons or 17 lbs. After the rigorous selection process, the wood is carved into two symmetrical plates, the upper and lower bodies, each painstakingly shaped to exhibit what are called "Chladni Patterns." The importance of this technique is to observe the mode shapes, different patterns formed on a violin when different frequencies are applied to it.

These patterns can be tested by using a loudspeaker to vibrate the bodies and observing the patterns formed by some black sand sprinkled onto the plates; resonance induces enough motion over the plates to cause the sand to bounce about [3]. "Chladni Patterns" (Fig. 2) are useful as they indicate whether the wood must be further shaped or thinned, with a thinner plate resulting in more pronounced pattern response. As the pattern must be very exact, final adjustments must be made by a very skilled craftsman, one who knows how each subtlety in the patterns will affect the final sound of the violin. Wikimedia Commons Wikimedia Commons Figure 3: A violin bridge has a vast effect on the transfer of sound. While precisely shaped plates do contribute significantly to the sound produced by a violin, the bridge (Fig. 3), though small in size, has vast effect on the transfer of the sound to these wooden plates. In fact, the bridge is so important in sound production that it is often referred to as the heart of the violin. The bridge serves two purposes. It holds the strings; but more importantly it transfers vibrations from the strings to the belly, which then transmits those vibrations to the body through the sound post and the bass bar.

Since the bass bar and the sound post are connected to the bridge, they also vibrate and in turn rock the belly, causing the whole violin to vibrate. This complete vibration induces waves in the air inside the violin, thereby changing the original vibration caused by the strings into sound that is emitted through the f-holes and...Voila! The violin produces its beautiful, familiar sound. Interestingly, the bridge transmits power to the body at frequencies from about one to four kHz, the range at which the ear is most sensitive. Thus the bridge, although very small relative to other parts of the violin, contributes a great deal in sound and timbre to the violin. It is important to remember that the placement of the bridge is equally important in the construction of a violin. It should be placed exactly between the fingerboard and the tailpiece vertically, while perfectly horizontal between the two f-holes. This is to ensure that the violin, if played correctly, produces the ideal sound. Moving the bridge even a centimeter from its optimal position can change the overall sound of the violin. To better understand this consequence, think of the bridge like a rubber band held taut between two fingers. Strum on it, and it makes a particular sound.

However, if you stretch the rubber band and strum on it again, a higher frequency sound is produced. Similarly, changing the position of the bridge could disrupt the desired sound of a violin. Finally, the type of bridge used depends on the strings selected. A violin needs a high bridge for low tension gut core strings or a low bridge for tighter metal or synthetic strings. The reason behind this is that metal strings are harder to bow because they require higher tension than gut core stings. But since tension is needed to produce good sound, yet not much should be added if metal strings are used, the lower bridge comes in handy. A low bridge has less tension than a high one, which helps to maintain the perfect tension needed in producing quality sound. The Interactions between String and Bow The importance of choosing the right strings for a violin can be compared to selecting tires for a car. Just like poorly made tires can result in a squeaky ride, selecting low quality strings will likewise yield cacophonous noises when a violinist attempts to stroke the strings. Each string on a violin is responsible for a distinct note. The E string, the highest note, is usually made of metal because metal has the highest tension and is capable of producing the highest frequency sound.

On the other hand, the G string -- the lowest note -- is made of gut core string that has far less tension than metal and produces low frequencies. To play the violin, the bow, which is composed of horse hair stretched across a long strip of wood, is pulled across the strings. Horse hair is used because of its electrostatic qualities. It acts like a magnet, attracting particles of rosin that help stick the bow to the strings. The more the bow is "glued" to the strings, the richer the sound it will produce. The friction between the hair and the strings causes the strings to vibrate and generate sound waves. To the naked eye, the string appears as though it is moving back and forth, but in actuality it is moving in a V-shape. This observation was first discovered by Hermann von Helmholtz 140 years ago, and since then violinists have tried to achieve the "Helmholtz Motion," where "smooth playability and good tone" of a bowed-string instrument are accomplished.

Helmholtz motion is characterized by the bow stroking the string and creating a single corner or indentation in the string that travels back and forth on the string with an slightly parabolic structure, or envelope. The corner then sticks to the bow as they touch one another. While the corner is on the shorter part of its journey, between the bow and the bridge, the string slips under the bow [4]. The Finale Imagine that you are seated in a dark hall. Suddenly the hall lights up and people around you start applauding madly. The woman on stage is proudly displaying a violin. She is none other than Midori Goto, a child prodigy. Then the lights dim and the audience takes their seats. Midori starts playing slowly at first, but then her bow begins to move so fast that you would think it was going to fly out of her hand at any given moment. In the corner of the hall, you gaze in awe as she mesmerizes you with the awe-inspiring sound that comes from her teeter-tottering bow. It is indeed amazing how one thin piece of wood can produce such incredible sounds when it touches the violin strings.

Although the sounds are beautifully intangible, the phenomenon of this musical instrument can reveal itself through the examination of the brilliant engineering behind it. References [1] Cyril Benoit, et al. "Violin: Origin." Internet: ​quest. org/27178/en/section​/1/, 1999 [1 Apr. 2005]. [2] David D. Boyden. The history of Violin Playing from its Origins to 1761and Its Relationship to the Violin and Violin Music. New York: Oxford University Press, 1990. [3] John Smith and John Tann, et al. "Chladni Patterns for Violin Plates." Science@UNSW. Internet: ​.edu.au/~jw/chladni.​html, 2004 [2 Apr. 2005]. [4] Stefania Serafin, Smith III, and Julios O., et al. "An Investigation of the Impact of Torsion Waves and Friction Characteristics on the Playability of Vitual Bowed Strings." IEEE Workshop on Applications of Signal Processing to Audio and Acoustics.

Internet: ​nford.edu/~serafin/S​erafinEtAl.pdf, pp. 17-20, Oct. 1999 [2 Apr. 2005]. [5] Frederick Bueche. Principles of Physics. 3rd ed. New York: McGraw-Hill, 1977. [6] Carl Courvoisier. Technics of Violin Playing on Joachim's Method. London: E. Shore and Co., 1899. [6] Lothar Cremer. The Physics of the Violin. Trans. John S. Allen. Cambridge, Mass.: MIT Press, 1984. [7] Kristi Ann Hughes. "The History of the Violin." Internet: ​olin-lessons.com/vio​lin_history/index.as​p., 28 Dec. 2004 [1 Apr. 2005]. Information on this web site is developed primarily by students, is provided for informational purposes only and is not a substitute for professional or technical advice or expertise. You should not use the information on this web site in lieu of expert advice.

Illumin makes no representations or guarantees of any kind, express or implied, concerning the accuracy, integrity, or quality of information presented herein. Illumin and the University of Southern California assume no liability for any damages arising from inappropriate use of such information. All viewpoints and opinions contained in Illumin articles and article comments are those of their respective authors and do not necessarily reflect the opinions of the Illumin editorial staff, the University of Southern California, or its Board of Trustees. ©2012 Illumin . All rights reserved.

Question: What name is given to the sound hole on a violin?
Answer: F-Hole